Are wheel weights getting harder

[Marlin Junky]

As I was melting a bunch of clip-on type wheel weights last weekend, while doing my final inspection I happened to notice some long ones... about 4 to 5 inches... that were painted light gray and a bit thinner than usual. Because they were painted (enameled I think) I didn't bother to do a scratch test so I reached for the magnet and they proved to be non-ferrous. Still not sure whether they were lead based, I gripped both ends of one and applied the bend test. The weight did not bend anywhere near as easy as the old time "Micro" weights. In fact the "modern" weights tend to break at the clips whereas the old time weights can be folded over or bent in half without breaking. Wondering weather I finally ran across the dreaded zinc wheel weight, I decided to stick one end of the suspect weight into my 580 to 600F pot of partially melted lumpy lead. After placing one end of the weight into the melt for about 5 to 10 seconds it did melt. What are we seeing here... a trend toward more Sb in our wheel weights? Or what is it that's making them so hard?

After rendering 200 pounds of alloys into ingots I've got bullet metal that I can barely scratch with my thumb nail. If this stuff pours good boolit, I'll be more than happy because there doesn't seem to be much need for a hardening component. However, I'm concerned that I introduced unwanted elements into my boolit metal. I do a pretty good job of separating my wheel weights into clip-on, glue-on and steel/suspect categories before I fire up the rendering furnace but it seems like each time I make ingots, they come out a little harder than the time before.

MJ

[Pop Gun]

I seriously doubt that they are getting harder. Especially with the need to have flexible stick on types for these new wheels today. As an example, my last batch (I smelt about 1000 lbs at a time for consistency) measures 14 BHN because I had some WW from the 60s to add. Now we hear of mixes as soft as 9 BHN.

When I started with WW in the 60s, they were supposed to be 9% antimony. They would turn a dark grey color in ingots. And after you molded with them, the bullets would ring if they came together. Then they got cut down in the 70s to about 6%. Late 70s to early 80s to about 4% which some believe they are today. I think that today, they are even softer which is why I won't add more than 2% tin so I don't exceed my antimony content and get soft spot formations.

What you may not realize is that that lead will harden for up to a month. So if they are that hard now ............ Without a tester though, you won't know how to mix that to your best advantage. Smart thing to do might be to have someone here run a test on what you have after you mold a couple of bullets. If you PM me when the time comes, I'll run'em.

[eka]

MJ, I'm starting to see Zinc now on a regular basis. The last three or four smelting sessions yielded one or two zinc weights in each pot. I kept the temp. down and just scooped them right out. They seem to take on a dull gold color when heated. I bought a turkey burner to throw out some heat, but now I'm carefully using the thermometer and poking along at 650F to 675F.

Keith

[fecmech]

The last batch of wheel wts that I rendered ended up in the 18 brinnel range. I did a 5 gal bucket full and could possibly have mixed in some zinc but the metal is casting good uniform bullets in 9mm,.38 and .45acp. The metal seems to flow well and bullets cast great with just the ww mix. If there is zinc in the mix it does not seem to be hurting anything. Nick

[Marlin Junky]

For the sake of clarification:

I'm referring to clip-on wheel weight hardness. I cull the much softer glue-on weights and melt them separately. With out a doubt, the average wheel weight I encountered 30 years ago was not brittle. In contrast, a bucket of wheel weights collected recently contains weights in all sorts of hardnesses and some are brittle... even the one's that melt at less than 650F.

EKA,

At what temp. do the zinc wheel weights melt? Is it possible to bend a zinc WW at all before breaking it? The steel WW's I fish out take on a brown/gold color which is pretty much the color steel changes to when heated to about 600F. Are you testing the WW's you're calling zinc with a magnet?

[largecaliberman]

For the sake of clarification:

I'm referring to clip-on wheel weight hardness. I cull the much softer glue-on weights and melt them separately. With out a doubt, the average wheel weight I encountered 30 years ago was not brittle. In contrast, a bucket of wheel weights collected recently contains weights in all sorts of hardnesses and some are brittle... even the one's that melt at less than 650F.

EKA,

At what temp. do the zinc wheel weights melt? Is it possible to bend a zinc WW at all before breaking it? The steel WW's I fish out take on a brown/gold color which is pretty much the color steel changes to when heated to about 600F. Are you testing the WW's you're calling zinc with a magnet?

Zinc melts at 787.244F. WWs - 630F and Pb - 621.5. Best to keep the head between 630F to 650F. When smelting, I would flux out as much as the junk and turn the heat down just a tad to 650F and let the melt sit for about an hour. [smilie=1: This way, I will give the the chance for the zinc (if any) to "solidify", cool and float to the top then throw in some NEI flux and repeat the process three more times.:castmine:

[felix]

If zinc is suspected, it is best to melt from the bottom only, and do not stir the pot. After all is melted plus a half hour, scrape whatever is on top off. Then and only then flux. ... felix

[ron brooks]

Now I'm getting confused. I thought that if yo kept you smelting temperature to 650 that all of the Zinc Clips would float to the top. Of course no heat from the top or you could melt them that way. Am I oversimplifing?

Thanks,

Ron

[felix]

Zinc won't sink unless stirred and fluxed in. You don't care if it is melted or not if you take off the top layer of the melt. As the lead melts it sinks to the bottom slowly, very slowly. When zinc melts, it will stay on top, or float to the top in time. Zinc alloys will melt at some temp we know nothing about as far as we are concerned. Hopefully, the zink will stay hooked up with whatever it is hooked with, and the whole shootin' match will rise to the top. ... felix

[grumpy one]

Ron, I don't think you can be at any risk of melting zinc if you keep your pot below 700 F. The problem, if there is one, comes after you've melted zinc into a lead alloy by using a vertically-mounted F18 engine under your pot and then run all four stages of afterburner, to melt a few tons of alloy pretty quickly. The temperature gets way above 800 F, any zinc present gets melted into the alloy, and the problem is to get the zinc out. The zinc-lead alloy will melt at less than 700 F unless the zinc content is pretty high, so you need to use Felix's method to remove most of the zinc and make the alloy more or less usable.

My method is to use both belt and suspenders - I sort out the non-lead items and toss them in the skip before I start, then I keep the pot below 700 F as well. I always find a few floaters that I've missed, because I'm a lazy sorter. When I have a item I'm unsure about, I put it in the pot and swirl it around for a while to see if it gets any smaller. The trickiest ones are some of the lacquered stick-ons, plus the weird weights that BMW use as original equipment. For both of these types I find some of them are lead, and melt in the pot. Some of them are not lead, and don't melt, so I toss them in the garbage. So far this approach seems to work, as far as I can tell.

The main difficulty I find is that stick-on weights vary a lot. There are some with almost no antimony - a strip of these twists with very little force, and I put them aside in the "pure lead" pile. There are some that can't be twisted by human hands and are lacquered - I conclude that these are not lead, and toss them out. In between, though, there are several different levels of twist resistance, probably due to different antimony contents. I hate to waste weights, so anything too hard to be considered almost-pure lead ends up being classified was WW. There aren't many of them, so it probably doesn't matter much.

Geoff

[targetshootr]

They're getting much harder. To find! (Couldn't hep it.) I hover over the pot and start skimming as soon as clips float so it only reaches max temp after it's free of all junk.

[The Double D]

Don't forget to mail me the zinc for safe and sanitary disposal at no charge.

[Sven Dufva]

Zinc won't sink unless stirred and fluxed in. You don't care if it is melted or not if you take off the top layer of the melt. As the lead melts it sinks to the bottom slowly, very slowly. When zinc melts, it will stay on top, or float to the top in time. Zinc alloys will melt at some temp we know nothing about as far as we are concerned. Hopefully, the zink will stay hooked up with whatever it is hooked with, and the whole shootin' match will rise to the top. ... felix
If you allredy melt in zinc in alloy.
I have talk with an metalurgist on Boliden expert on lead alloys and he told me the best way to take Zink away is to to boil the alloy.
But be carful boil gas is poisson.

[Lloyd Smale]

what ive had luck doing as far as smelting goes along with felix. I have a waterheater thats cut in half with a valve on the bottom. I fill it with wws and put it in my fire pit and build a fire. I let it cook till everything is melted and then open the bottom valve and poor ingots without fluxing or disturbing the alloy. Ive done batches like that that i know have had zinc in them and its never given me a problem. After everything cools and you dump the clips you will notice a lead residue on the clips. Im about betting thats the zinc in the alloy clinging to to steel clips after it cools. I cant prove this but it looks just like the residue that zinc will leave in your pot and on your molds if you cast with zinc. I also take about the last 10lbs of the ingots i make and put them in a bucket seperately incase they are contaminated. But from the batches ive done like this so far the last 10lbs has casted as well as the first.

[Marlin Junky]

what ive had luck doing as far as smelting goes along with felix. I have a waterheater thats cut in half with a valve on the bottom. I fill it with wws and put it in my fire pit and build a fire. I let it cook till everything is melted and then open the bottom valve and poor ingots without fluxing or disturbing the alloy. Ive done batches like that that i know have had zinc in them and its never given me a problem. After everything cools and you dump the clips you will notice a lead residue on the clips. Im about betting thats the zinc in the alloy clinging to to steel clips after it cools. I cant prove this but it looks just like the residue that zinc will leave in your pot and on your molds if you cast with zinc. I also take about the last 10lbs of the ingots i make and put them in a bucket seperately incase they are contaminated. But from the batches ive done like this so far the last 10lbs has casted as well as the first.

Very interesting way to process WW's. I even have a decommissioned water heater on hand but didn't think they were heavy enough to melt lead in.

MJ

[The Double D]

Lloyd,

Have you compared the weight of the first ingot pour with the last ingots poured?